Method and system of generating geometric characteristics of a digitally encoded image

ABSTRACT

The system of generating geometric characteristics of a digitally encoded image comprises a display device ( 2 ) capable of displaying a digitized image, communicating with a control unit ( 4 ), and comprising a man-machine interface ( 6 ) and means of supplying data ( 3 ) to the system via said man-machine interface ( 6 ). The system also comprises: 
         a display means ( 7 ) for displaying a digitally encoded image on the display device ( 2 ),    a first delimiting means ( 8 ) for delimiting a portion of the image representing a substantially flat surface,    a processing means ( 9 ) for applying a predetermined deformable geometric pattern to the image in the position of said delimited image portion and deforming the pattern so as to make it correspond to said image portion, and    a determination means ( 10 ) for determining geometric characteristics of said surface from the deformation of the pattern.

The present invention relates to the generation of geometriccharacteristics of a digitally encoded image, and more particularly to amethod and a system of generating geometric characteristics of a digitalimage to allow changes of surface coatings to be simulated on the image.

There are methods implemented by computers that allow changes of surfacecoatings to be simulated from a digitally encoded image. Such methodsare normally restrictive, because they entail lengthy preparatory workto create a specific image including reference elements enabling thegeometric characteristics of the image to be deduced.

In this respect, reference can be made to the document GB 2 404 512which discloses a method implemented by computer to determine geometriccharacteristics of an image. The image must originate from a photographtaken by positioning, in an accurate and predetermined way, referenceelements in the form of patterns on different flat surfaces to bephotographed, normally walls, floors or ceilings of rooms. The renditionin the image of these elements and the knowledge of the dimensions ofthe elements makes it possible, according to the method implemented, toextract geometric characteristics of the image, in order to be ablesubsequently to simulate different coatings on the surfaces of the roomin the image.

Such a method is difficult to implement by an unskilled user, andrequires lengthy preparation work in order to obtain an image that canbe modified by changing, for example, the coatings of certain surfaces.

Furthermore, the relative small size of the reference elements placed onthe surfaces to be photographed leads to a lack of accuracy in theextraction of the geometric characteristics.

The invention therefore seeks to remedy these drawbacks, and proposes todetermine geometric characteristics of a digitally encoded image,without requiring preliminary processing of the surfaces whenphotographing surfaces on which there is a desire to simulate anothercoating.

Thus, there is proposed, according to one aspect of the invention, amethod of generating geometric characteristics of a digitally encodedimage. According to this method, the image is displayed, and a portionof the image is delimited, representing a substantially flat surface. Apredetermined deformable geometric pattern is then applied to the imagein the position of said delimited image portion, the pattern is deformedso as to make it correspond to said image portion, and geometriccharacteristics of said surface are determined from the deformation ofthe pattern.

There is therefore no need to perform lengthy surface preparationoperations before taking a photograph to be used as a basis for thedigitized image.

The geometric characteristics are determined from the deformation of thegeometric patterns mapped to the different surfaces.

Furthermore, the accuracy of the geometric data extracted is enhanced.

The geometric characteristics include in particular the angles formed bytwo pairs of straight lines of the image, respectively representative oftwo pairs of straight lines that are parallel in reality, the directionof the straight lines of one pair being perpendicular to the directionof the straight lines of the other pair. The geometric characteristicsalso include the scale ratios between the actual sizes of the elementsand their size on the image.

In a preferred embodiment, a coating is selected from a set of coatingsstored in a database, and an image is generated of said surface coveredby said coating according to the geometric characteristics of thesurface.

It is possible to simulate changes of surface coatings, and to displaythe result immediately. It is then easy to choose the coatings to beplaced on the surfaces, such as wood floors, paints or wallpapers.

The invention makes it possible, from a simple digitally encodedphotograph, to immediately display an unlimited number of changes ofdecoration of a room, and thus to be able to choose the decoration ofchoice for that room.

Naturally, the invention applies to the interior surfaces of a room aswell as to the exterior surfaces of a building.

Advantageously, the pattern is a grid comprising a criss-cross patternof a predetermined set of rows and columns of individual squares ofpredetermined surface.

Such a pattern is simple, easy to manipulate, and facilitatesgeometrical data computations.

In a first embodiment, for each of the two directions of said imageportion representing said surface, the actual size of an element of saidsurface displayed according to an axis of the superimposed grid isindicated.

This makes it possible to indicate accurately distances according to thetwo axes of the grid, and thus to determine the other necessarydistances, according to both axes.

In a second embodiment, the number of rows and columns of the grid isadapted according to the size of a side of an individual square of thegrid and the dimensions of said surface.

There are then indicated, in a different way, the distances according tothe two axes of the grid, in order to make it possible to determine theother necessary distances, according to both axes.

Advantageously, one or more portions of said image are delimited,corresponding to the representation of objects located in front of saidsurface.

Thus, the change of coating will not be applied to these elements, whichare located in front of the surface for which there is a desire tosimulate a change of coating.

Furthermore, a zoom is used to refine the delimiting of said portions ofsaid image corresponding to the representation of said objects locatedin front of said surface and/or the delimiting of said portion of saidimage representing said surface.

The zoom is used to define more clearly the outlines of objects andsurfaces, in order to obtain a more accurate result.

Furthermore, the geometric patterns respectively superimposed on aplurality of portions of the image representing substantially flatsurfaces are adjusted.

The geometric patterns are accurately adjusted, manually orautomatically, to the respective image portions. Furthermore, when twosurfaces on which there is a desire to simulate another coating meet ona common side, the geometric patterns are automatically adjusted sothat, when the new image is generated, the two respective coatings ofthe surfaces meet perfectly.

Advantageously, the respective positions of said delimited imageportions are pre-displayed and/or the respective positioning of thegeometric patterns is pre-displayed.

Such a pre-display makes it possible to check the respective positioningof the cut out image portions, before starting the simulation process.It is also possible to check the correct positioning of the geometricpatterns on the image portions corresponding to the flat surfaces.

Furthermore, it is possible to define the respective positions of saiddelimited image portions.

This makes it possible to define the positioning of elements of theimage relative to each other.

It is also possible to group a number of delimited portions of the imagerepresenting substantially flat surfaces, to generate an image of saidgrouped surfaces covered simultaneously by one and the same selectedcoating.

By being able to group or separate a set of delimited portions of theimage it becomes possible to choose a coating common to a group ofsurfaces and to simulate it on all these surfaces at one and the sametime.

Advantageously, the shadows and lights present on said surfaces aretaken into account, and said shadows and lights are restored on thegenerated images comprising the surfaces covered by respective coatings,taking into account said coating.

It is then possible to display the effects of the lighting on thesimulated coating.

In a preferred embodiment, unprocessed images, images comprising saiddelimited portions and images with simulated surfaces covered by acoating are memorized.

It is possible to memorize all the images, in order to be able to havethem available when necessary, and thus avoid recommencing work that hasalready been done before.

According to another aspect of the invention, there is also proposed acomputer program stored on a data storage medium, which comprisesinstruction codes suitable for implementing a method as describedpreviously, when executed in a computation module.

There is also proposed, according to another aspect of the invention, asystem of generating geometric characteristics of a digitally encodedimage comprising a display device capable of displaying a digitizedimage, communicating with a control unit, and comprising a man-machineinterface and means of supplying data to the system via said man-machineinterface. The system comprises a display means for displaying adigitally encoded image on the display device, and a first delimitingmeans for delimiting a portion of the image representing a substantiallyflat surface. The system also comprises a processing means for applyinga predetermined deformable geometric pattern to the image in theposition of said delimited image portion and deforming the pattern so asto make it correspond to said image portion, and a determination meansfor determining geometric characteristics of said surface from thedeformation of the pattern.

Advantageously, the system also comprises a selection means forselecting a coating from a set of coatings stored in a database, and ageneration means for generating an image of said surface covered by saidcoating according to the geometric characteristics of the surface.

In a preferred embodiment, the processing means is suitable for applyinga grid comprising a criss-cross pattern made up of a predetermined setof rows and columns of individual squares of predetermined surface.

In a first embodiment, the system comprises an indication means forindicating the actual size of an element of said surface displayedaccording to an axis of the superimposed grid, for each of the twodimensions of said image portion representing said surface.

In a second embodiment, the system comprises an adaptation means, foradapting the number of rows and columns of the grid according to thesize of a side of an individual square of the grid and the dimensions ofsaid surface.

Advantageously, the system comprises a second delimiting means fordelimiting one or more portions of said image corresponding to therepresentation of objects located in front of said surface.

In a preferred embodiment, the system comprises a zoom means forrefining the delimiting of said portions of said image corresponding tothe representation of said objects located in front of said surfaceand/or the delimiting of said portion of said image representing saidsurface.

In an advantageous embodiment, the system comprises an adjustment meansfor adjusting the geometric patterns respectively superimposed on aplurality of portions of the image representing substantially flatsurfaces.

In a preferred embodiment, the system comprises a pre-display means forpre-displaying the respective positions of said delimited imageportions.

Furthermore, the system comprises a means of modifying the respectivepositions of said delimited image portions.

Advantageously, the system comprises a grouping means for grouping anumber of delimited portions of the image representing substantiallyflat surfaces. Said generation means is capable of generating an imageof said grouped surfaces simultaneously covered by one and the sameselected coating.

In a preferred embodiment, the system comprises a masking means fortaking into account the shadows and lights present on said surfaces, andrestoring said shadows and lights on the generated images comprising thesurfaces covered by respective coatings, taking into account saidcoating.

Furthermore, the system comprises a memorizing means for memorizingunprocessed images, images comprising said delimited portions and imageswith simulated surfaces covered by a coating.

Other objects, characteristics and advantages of the invention willbecome apparent from reading the description that follows, given purelyas a non-limiting example, and made with reference to the appendeddrawings in which:

FIG. 1 is a block diagram illustrating a first embodiment of a systemaccording to the invention;

FIG. 2 is a block diagram illustrating a second embodiment of a systemaccording to the invention;

FIGS. 3 a and 3 b illustrate a first way of implementing a methodaccording to one aspect of the invention;

FIGS. 4 a and 4 b illustrate a second way of implementing a methodaccording to one aspect of the invention; and

FIGS. 5 to 24 illustrate an implementation by computer of the methodaccording to one aspect of the invention.

As can be seen in FIG. 1, the system 1 comprises a display device 2, forexample a screen. A module for supplying data 3, comprising, forexample, a keyboard or a mouse, enables a user to supply data to thesystem I.

The system 1 also comprises a control unit 4 and a database 5 ofpredetermined patterns corresponding to coatings that there is a desireto simulate on portions of a digitally encoded image, representingsubstantially flat surfaces.

The control unit 4 comprises a man-machine interface 6, processing inparticular the data supplied by the module for supplying data 3,generally via a computer keyboard or mouse.

The control unit 4 comprises a display module 7 that can be used todisplay a digitally encoded image on the display device 2. The displaymodule 7 can also be used to swivel the image on the display device 2,if it is not displayed the right way round.

The control unit 4 also comprises a first delimiting module 8 fordelimiting a portion of the image representing a substantially flatsurface.

The control unit 4 also comprises a processing module 9, that can beused to apply a predetermined deformable geometric pattern to adelimited image portion by means of the first delimiting module 8, andthat can be used to deform the geometric pattern so as to make itcorrespond to said image portion representing a substantially flatsurface.

A determination module 10 makes it possible, to determine geometriccharacteristics of a surface for which said image portion has beendelimited, from the deformation of the pattern.

In the description that follows, the geometric pattern is a grid.Naturally, the invention applies generally to any other geometricpattern that might be appropriate.

A selection means 11 can be used to select a coating for each surface orgroup of surfaces to be simulated, from the set of coatings stored inthe database 5. A generation means 12 can be used to generate an imageon which one or more surfaces are covered by the or each selectedcoating according to the geometric characteristics of the surface.

The processing means 9 can be used to apply a grid comprising acriss-cross pattern consisting of a predetermined set of rows andcolumns of individual squares of predetermined surface.

An indication means 13 can be used to indicate the actual size of anelement of said displayed surface, according to an axis of thesuperimposed grid, and this for each of the two dimensions of said imageportion representing said surface. In other words, according to eachaxis of the superimposed grid, the actual size of an element of saidsurface is indicated.

A second delimiting module 14 can be used to delimit one or moreportions of the image corresponding to the representation of objectslocated in front of a surface to be simulated.

A zoom module 15 can be used to refine the delimiting of the portions ofthe image that correspond to the representation of objects located infront of the surface and/or the delimiting of the portion of the imagerepresenting a surface to be simulated.

An adjustment module 16 can be used to adjust the geometric patterns,namely the grids respectively superimposed on a number of portions ofthe image representing substantially flat surfaces. Such an adjustmentmakes it possible to make the different grids consistent with eachother.

The system 1 also comprises a pre-display module 17 that can be used toroughly pre-display the respective positions of said delimited imageportions and/or the respective positioning of the geometric patterns.

A definition module 18 can be used to define respective positions of thedelimited image portions.

A grouping module 19 can be used to group or separate a number ofdelimited portions of the image representing substantially flatsurfaces. Thus, a number of grouped image portions corresponding to anumber of surfaces can be simulated covered simultaneously by one andthe same selected coating.

A masking module 20 can be used to take into account the shadows andlights present on the surfaces, and to restore the shadows and lights onthe generated images comprising the surfaces covered by the respectiveselected coatings, and this taking into account said coating.

A memorizing module 21 can be used to memorize unprocessed images,images comprising delimited portions and images with simulated surfacescovered by one or more coatings. The memorizing of such images makes itpossible to avoid repeating work already done, and to compare a numberof final results in order to choose the preferred result.

As a variant, the system represented in FIG. 2 comprises an adaptationmodule 22 in place of the indication module 13. The adaptation module 22can be used to adapt the number of rows and columns of a grid accordingto the size of a side of an individual square of the grid and thedimensions of the surface corresponding to the grid.

This variant shows another way of indicating orders of size that areuseful to the generation of geometric characteristics of a digitallyencoded image.

FIGS. 3 a and 3 b represent an exemplary implementation of the methodaccording to one aspect of the invention.

In the application represented, it concerns enabling an operator tosimulate a change of material, or colour, of a coating, paint or otherof a bedroom, as much for the floor, ceiling and wall surfaces as forfurniture or decoration items. In practice, furniture or decorationitems can be broken down into a set of substantially flat surfaces.

The first step is to display a digitally encoded image (step 30). Duringthis display of an image to be processed, the image can be swivelled onthe display device 2 to position it the right way round, if it is notdisplayed by default the right way round, according to its encoding.Such an example is illustrated in FIGS. 5 and 6. The display of theimage to be processed, and its swivelling if necessary, are implementedby the display means 7 and the display device 2.

A portion of the image is delimited (step 31), representing a flatsurface on which there is a desire to simulate a coating other than thatactually present.

In the description that follows, it is assumed that the display device 2is a screen, and that the module for supplying data 3 comprises akeyboard and a mouse.

The delimiting of the image portion representing a flat surface isperformed using the first delimiting means 8. This delimiting isperformed using the mouse 3 and the screen 2, as illustrated in FIGS. 7and 8. During this delimiting, it is possible to use a zoom module 15 inorder to refine the delimiting of the outline of the portion of theimage representing the flat surface.

Image portions are delimited representing objects located in front ofthe flat surfaces that have been delimited. Such objects include, forexample, an occasional table on which is placed an alarm clock, or evena window, as illustrated in FIGS. 9, 10, 11, 12 and 13. FIG. 10illustrates the use of a zoom to delimit more accurately the objectslocated in front of the flat surface and to be excluded from the coatingsimulation. The delimiting of the image portions representing objectslocated in front of these flat surfaces is performed using the seconddelimiting module 14. The zoom is implemented by means of the zoommodule 15.

These delimitings (steps 31 and 32) of image portions are performed forall the substantially flat surfaces on which there is a desire tosimulate another coating, and for all the image portions representingobjects located in front of these flat surfaces to be simulated. FIGS.14 and 15 illustrate such delimitings of image portions corresponding toflat surfaces and objects located in front of the latter. In FIGS. 14and 15, three flat surfaces are thus delimited, two walls and a floor ofa bedroom. The various objects, such as the occasional table, the bedand the trunk, which are to be excluded from the surfaces on which thereis a desire to simulate another coating, appear in the display. FIG. 15represents a refinement of the delimiting curves of FIG. 14.

A deformable geometric pattern is applied (step 33) to the delimitedimage portions representing a flat surface to be simulated.

The deformable geometric pattern is deformed (step 34), in order for thegrid to be superimposed on the associated image portion representing aflat surface. FIGS. 16 and 17 illustrate the application and deformationof the geometric pattern, in this case a grid, to the bedroom.

The application and deformation of the grids are performed by theprocessing module 9 and are intended to acquire information relating tothe geometric characteristics of the grid and the deformation of thegrid to make it coincide with a surface being examined.

For an image portion representing a surface to be simulated, the size ofan element is indicated (step 35) according to each of the two axes ofthe grid. In other words, for each image portion representing a surfaceto be simulated, it is necessary to define a height of an element and awidth of an element. This size indication (step 36) is illustrated byFIGS. 18 and 19. FIG. 18 illustrates the indication of the height of thewall located behind the bed, and FIG. 19 illustrates the indication ofthe width of the bed. For the image portion corresponding to the surfaceof the wall located behind the bed, there is even indicated a heightindication and a width indication. This size indication is performed foreach of the image portions representing a surface to be simulated, foreach axis of the grid, by the indication module 13.

It is possible to perform a pre-display (step 36) with which to displaythe various grids of the image in order to check their consistency fromone to the next, by means of the pre-display module 17. FIG. 20illustrates a pre-display of the image representing the grids andobjects cut out.

The grids are adjusted (step 37) between themselves. The adjustment canbe done manually or automatically, by means of the adjustment module 16.

The position of the various elements corresponding to the delimitedimage portions is defined (step 38), as illustrated in FIG. 21, throughthe definition module 18.

It is possible to pre-display (step 39) the relative positions of theseelements, as illustrated in FIG. 21.

The shadows and lights are taken into account (step 40), by defining fora surface, on the image, a location of the reference colour, that is, areference without bright underexposure or bright overexposure. Themasking module 20 allows this taking into account of the plays of lighton the surfaces, and for them to be extrapolated on the simulatedcoatings. The location of the reference colour is illustrated in FIG.22.

The shadows and lights are taken into account, by creating a shadowmask, simultaneously using the reference colour, and a deletion, ifnecessary, of undesirable patterns from the photograph, for example awallpaper pattern, by means of an image filter called a low-pass filter.

It is possible to perform a surface grouping (step 41) if there is adesire to simulate a plurality of portions of the image representing aplurality of surfaces with one and the same coating. An example ofgrouping of two surfaces, in this case the two walls, is illustrated inFIG. 23. The grouping module 10 can be used, via the man-machineinterface module 6, the display device 7 and the computer mouse 3, toselect the two surfaces to be grouped, by clicking for example at thepoints represented by crosses in FIG. 23, each click selecting thecorresponding surface.

For each surface or group of surfaces, a coating that there is a desireto simulate is chosen (step 42), by means of the selection module 11 andthe database 5.

The geometric characteristics of the different surfaces on which thereis a desire to simulate a coating are determined (step 43).

An image is generated (step 44), on which the chosen coatings have beensimulated on the corresponding surfaces.

FIG. 24 illustrates a simulation of the bedroom with striped wallpaperon the walls and a wood floor.

The initial, final and intermediate images are memorized (step 45) so asto be able to reuse them judiciously without having to reconstruct them.

As a variant, as illustrated in FIGS. 4 a and 4 b, the size indication(step 35) is replaced by an adaptation (step 46) of the number of rowsand columns of the grids according to the predetermined dimensions of anindividual tile of the grids, in order that the predetermined surfaceassociated with an individual tile should correspond to the surface tobe simulated.

The determination and generation modules use a mapping between an actualcoating tile and a tile of the grid of the image. The scale of thetextures is deformed and modified, by the mapping process, as explained,for example, in the document “Perspective Mappings BetweenQuadrilaterals” by David Eberly, available online fromhttp://geometrictools.com/Documentation/perspective2.pdf.

The invention makes it possible to generate geometric characteristics ofa digitally encoded image, easily and without restriction for the user.

Furthermore, the invention makes it possible to simulate as manycombinations of surface coatings as may be desired, in order to choosethe decoration of a room or an exterior, by displaying in advance theresult, which makes it possible to avoid many disappointments andregrets concerning the choice of coatings.

1. Method of generating geometric characteristics of a digitally encodedimage, comprising: displaying the image; delimiting at least a portionof the image, wherein the delimited portion represents a substantiallyflat surface; applying a predetermined deformable geometric pattern tothe image in the position of the delimited image portion; deforming thepattern so as to make it correspond to the image portion; anddetermining geometric characteristics of the surface from thedeformation of the pattern.
 2. The method of claim 1, furthercomprising: selecting a coating from a set of coatings stored in adatabase; and generating an image of the surface covered by the coatingaccording to the geometric characteristics of the surface.
 3. The methodof claim 1, wherein the pattern is a grid comprising a criss-crosspattern of a predetermined set of rows and columns of individual squaresof predetermined surface.
 4. The method of claim 3, wherein for each ofthe two directions of the image portion representing the surface, theactual size of an element of the surface displayed according to an axisof the grid superimposed is indicated.
 5. The method of claim 3, furthercomprising adapting the number of rows and columns of the grid accordingto the size of a side of an individual square of the grid and thedimensions of the surface.
 6. The method of claim 1, further comprisingdelimiting one or more portions of the image corresponding to therepresentation of objects located in front of the surface.
 7. The methodof claim 6, wherein delimiting the image comprises using a zoom torefine the delimiting of the portions of the image corresponding to therepresentation of the objects located in front of the surface and/or thedelimiting of the portion of the image representing the surface.
 8. Themethod of claim 7, comprising adjusting the geometric patternsrespectively superimposed on a plurality of portions of the imagerepresenting substantially flat surfaces.
 9. The method of claim 6,further comprising pre-displaying the respective positions of thedelimited image portions and/or the respective positioning of thegeometric patterns.
 10. The method of claim 6, further comprisingdefining the respective positions of the delimited image portions. 11.The method of claim 2, further comprising grouping a number of delimitedportions of the image representing substantially flat surfaces togenerate an image of the grouped surfaces covered simultaneously by oneand the same selected coating.
 12. The method of claim 1, furthercomprising accounting for the shadows and lights present on thesurfaces; and restoring the shadows and lights on the generated imagescomprising the surfaces covered by respective coatings, taking intoaccount the coating.
 13. The method of claim 12, further comprisingmemorizing unprocessed images, images comprising the delimited portionsand images with simulated surfaces covered by a coating.
 14. A computerprogram stored on a data storage medium, characterized in that itcomprises instruction codes suitable for implementing, when executed ina computation module, the method comprising: displaying an image;delimiting at least a portion of the image wherein the delimited portionrepresents a substantially flat surface; applying a predetermineddeformable geometric pattern to the image in the position of thedelimited image portion; deforming the pattern so as to make itcorrespond to the image portion; and determining geometriccharacteristics of the surface from the deformation of the pattern. 15.A system of generating geometric characteristics of a digitally encodedimage comprising: a display device capable of displaying a digitizedimage, communicating with a control unit, and comprising a man-machineinterface and means of supplying data to the system via the man-machineinterface comprising: a display means for displaying a digitally encodedimage on the display device; a first delimiting means for delimiting aportion of the image representing a substantially flat surface; aprocessing means for applying a predetermined deformable geometricpattern to the image in the position of the delimited image portion anddeforming the pattern so as to make it correspond to the image portion;and a determination means for determining geometric characteristics ofthe surface from the deformation of the pattern.
 16. The system of claim15, further comprising a selection means for selecting a coating from aset of coatings stored in a database, and a generation means forgenerating an image of the surface covered by the coating according tothe geometric characteristics of the surface.
 17. The system of claim15, wherein the processing means is suitable for applying a gridcomprising a criss-cross pattern made up of a predetermined set of rowsand columns of individual squares of predetermined surface.
 18. Thesystem of claim 17, further comprising an indication means or indicatingthe actual size of an element of the surface displayed according to anaxis of the superimposed grid, for each of the two dimensions of theimage portion representing the surface.
 19. The system of claim 17,further comprising an adaptation means, for adapting the number of rowsand columns of the grid according to the size of a side of an individualsquare of the grid and the dimensions of the surface.
 20. The system ofclaim 15, further comprising a second delimiting means for delimitingone or more portions of the image corresponding to the representation ofobjects located in front of the surface.
 21. The system of claim 20,further comprising a zoom means for refining the delimiting of theportions of the image corresponding to the representation of the objectslocated in front of the surface and/or the delimiting of the portion ofthe image representing the surface.
 22. The system of claim 15, furthercomprising an adjustment means for adjusting the geometric patternsrespectively superimposed on a plurality of portions of the imagerepresenting substantially flat surfaces.
 23. The system of claim 20,further comprising a pre-display means for pre-displaying the respectivepositions of the delimited image portions and/or the respectivepositioning of the geometric patterns.
 24. The system of claim 23,further comprising a means of defining respective positions of thedelimited image portions.
 25. The system of claim 16, further comprisinga grouping means for grouping a number of delimited portions of theimage representing substantially flat surfaces, the generation meansbeing capable of generating an image of the grouped surfacessimultaneously covered by one and the same selected coating.
 26. Thesystem of claim 15, further comprising a masking means for taking intoaccount the shadows and lights present on the surfaces, and restoringthe shadows and lights on the generated images comprising the surfacescovered by respective coatings, taking into account the coating.
 27. Thesystem of claim 15, further comprising a memorizing means for memorizingunprocessed images, images comprising the delimited portions and imageswith simulated surfaces covered by a coating.